As a gas turbine, there are gas turbines described in, for example. Patent Documents 1 and 2 below.
A rotor of the gas turbine described in Patent Document 1 has a rotor disk of each of a plurality of stages, and a plurality of blades fixed to the rotor disk. Further, a plurality of vanes of the gas turbine is disposed on the upstream sides of the blades of each of the plurality of stages. An upstream-side rim portion which protrudes to the upstream side and first and second downstream-side rim portions which protrude to the downstream side are formed at the rotor disk of each of the plurality of stages. The second downstream-side rim portion of the rotor disk is located further radially inward than the first downstream-side rim portion and faces the upstream-side rim portion of a downstream-side rotor disk adjacent to the downstream side of the rotor disk.
A seal housing which faces the second downstream-side rim portion of the rotor disk on the upstream side with respect to the vane and the upstream-side rim portion of the rotor disk on the downstream side with respect to the vane is fixed to the inside of the vane in the radial direction. A first upstream-side seal member which performs sealing between the seal housing and the first downstream-side rim portion of the upstream-side rotor disk, a second upstream-side seal member which performs sealing between the seal housing and the second downstream-side rim portion of the upstream-side rotor disk., and a downstream-side seal member which performs sealing between the seal housing and the upstream-side rim portion of the downstream-side rotor disk are provided at the seal housing.
In the gas turbine, a thermometer for measuring the temperature of gas in a disk cavity between the seal housing and the rotor disk on the upstream side and the rotor disk on the downstream side with respect to the seal housing is provided.
In the seal housing, a detection space in which a temperature detection end of the thermometer is inserted, a gas introduction path extending from the detection point space to the upstream side along an axis of rotation, and a gas discharge path extending from the detection end space to the downstream side along the axis of rotation are formed. An introduction port of the gas introduction path is located further to the upstream side than the first upstream-side seal member provided at the seal housing and on the outside in the radial direction. Further, a discharge port of the gas discharge path is located further to the downstream side than the downstream-side seal member provided at the seal housing and on the outside in the radial direction.
The thermometer detects the temperature of gas which flows in from the introduction port of the gas introduction path, that is, gas in an area of the disk cavity further on the upstream side and further on the outside in the radial direction than the first upstream-side seal member.
Further, in Patent Document 2, there is disclosed a thermometer in which a body portion of the thermometer is bent such that a detection end provided at the tip of the body portion can detect the temperature of gas in a target area in the disk cavity.